SAR-based scientific products in support to recovery from hurricanes and earthquakes: lessons learnt in Haiti from the CEOS Recovery Observatory pilot to the demonstrator

Since 2014, the Committee on Earth Observation Satellites (CEOS) has been working on means to increase the contribution of satellite data to recovery from major disasters. The 4 year-long Recovery Observatory (RO) pilot project, led by CNIGS with technical support from CNES [www.recovery-observatory.org], was triggered to address the needs of the Haitian community in the south-west of the country involved in recovery after the impact of Hurricane Matthew in October 2016. Following that experience, the RO Concept was published in an Advocacy Paper [1] and the RO Demonstrator Team was created with the aim to activate a series of 3 to 6 ROs after major events between 2021 and late 2023 [2].

It is with regard to the RO pilot and the latest RO demonstrator activation after the 7.2 Mw earthquake and Hurricane Grace occurred in August 2021, that the following lessons learnt in Haiti are discussed:

• technical achievements and challenges in the use of SAR data from high revisit sensors (e.g. Sentinel-1) and on-demand acquisitions from high resolution missions (e.g. COSMO-SkyMed, TerraSAR-X) for terrain motion and land surface change applications;
• the role that the collaboration with users and stakeholders can play to add value to SAR-based scientific products;
• capacity building and training enabling local champions and public stakeholders to effectively uptake SAR technology for their own duties of disaster risk management.

During the pilot, a wide-area regional analysis was undertaken by processing Sentinel-1 in ESA’s Geohazards Exploitation Platform [3], to identify areas affected by ground motions not suitable for reconstruction. The exercise also allowed the understanding of the factors limiting the exploitation of this resource by users (e.g. skill gap, limited internet connectivity).

The high resolution monitoring activity with ASI’s COSMO-SkyMed data, CNES’ Pléiades images and ground-truth validation over 3 priority areas defined by the Haitian users, allowed the identification of the following categories of surface changes:

(a) environmental, along the Grand’Anse River south of Jérémie, mixed with quarrying and unregulated waste disposal [4];

(b) geological, along the rock cliffs north-west of Jérémie where toppling and lateral spreading may be worsened by future disasters, thus causing potential risks to small villages and isolated dwellings;

(c) urban, within the outskirts of Jérémie due to reconstruction and new constructions in unstable areas;

(d) rural, due to landslides to be distinguished by similar signals associated with agricultural practices along the slopes in Camp Perrin.

This knowledge was used as the most up-to-date baseline to assess the impact of the August 2021 earthquake and hurricane, and the current process of recovery on south-west Haiti peninsula in the framework of the RO demonstrator activation. The RO collaborated closely with local partners and the CNIGS performed satellite based analysis of damage after the earthquake. A long-term objective of the RO remains strong capacity development of local actors.

 

References:

[1] https://www.gfdrr.org/en/publication/use-of-eo-satellites-recovery

[2] https://ceos.org/document_management/Working_Groups/WGDisasters/WGMeetings/WGDisasters_Mtg16_Virtual/CEOS_WGD16_RO_Demonstrator.pdf

[3] Cigna, F. et al. (2020) Proceedings of 2020 IEEE IGARSS, pp. 6867–6870. https://doi.org/10.1109/IGARSS39084.2020.9323231

[4] De Giorgi, A. et al. (2021) Remote Sensing, 13 (17), 3509. https://doi.org/10.3390/rs13173509